This application relates to systems for the delivery of accurate predetermined amounts of liquid through a plurality of relatively small conduits, specifically in the field of apparatus for the injection of tenderizing liquid and the like into animal carcasses for meat.
Automated systems are known for the injection of tenderizing liquid (which may contain a proteolytic enzyme) for the purpose of tenderizing and therefore upgrading lower grades of meat to make them more desirable to the consumer. Numerous prior systems for administering tenderizing solution have been proposed, for example, U.S. Pat. Nos. 3,232,209, 3,971,088, and 3,916,777.
A currently operating meat tenderizing system utilizes a pressure pot which delivers fluid through a single line to a flow meter, a counter, and then to a multitude of needle hoses which carry groups of injection needles on their ends. An intermittently operated pump with pressure sensitive operating means is utilized to hold the pressure to a desired level.
As a disadvantage of the above described prior art system, it has been found that it cannot be used in a continuous operation mode, with the individual operators of the injection needles opening at random times the valves controlling the needles to inject a desired amount of tenderizing solution, without encountering very substantial pressure variances in the system. These variances can range up to about 50 percent of the total pressure.
Because of this, when all the needles are inserted, the entire system is energized to open the valves controlling all needle headers so that all needles are opened to allow for the specific amount of fluid to be delivered into the carcass, so that the system operates under similar pressure conditions for each injection procedure.
The pressure of the system is of course critical, being an important factor, along with the volume or flow dependent upon the valves communicating with the open injection needles, for determining the amount of tenderizing solution which is actually injected into the carcass at each injection site.
The above prior art tenderizing solution injection apparatus is therefore not suitable for use on a continuous moving process line, as would be most desirable for large scale operations for tenderizing carcasses of beef or the like, since all of the needles must be inserted and simultaneously opened, in order to obtain uniform pressure conditions from carcass to carcass.
The liquid delivery system of this invention overcomes the above deficiencies, and is capable of use on a moving line of carcasses in which the individual operators of injection needles do not have to time their opening of the needles with respect to the other operators.
By this invention, as the carcasses come by the line, each individual operator inserts his injection needles at a specified location of the carcass, and then opens the valve allowing flow through the needle for a predetermined time, without regard to the activities of the other needle operators on the line. The carcass then continues down the line, where it is injected by other operators using other needles in different portions of the carcass, without major changes in the pressure of the system, even though the needles on the line may communicate with a common pressure system.
As a further advantage, various different carcasses moving down the line may be simultaneously undergoing treatment by the operators of the needles, which connect with a common pressure system. The system of this invention is capable of adjusting the open valve time of each needle simultaneously at different stations to account for the weight of the different carcasses simultaneously passing by each injection station.
This may be accomplished by automatic valve means, each having valve control means for opening the valve for a period of time which is automatically computed by a microprocessor system disclosed herein, responsive to the weight of the carcass being processed. This automatic system also provides a system for visually signalling that the carcass has been successfully injected by each needle at each station.